Is Low Level Laser Therapy (LLLT) Effective for Reducing Pain Experienced by Women With Provoked Vestibulodynia?

Plain-language summary

Provoked vestibulodynia (PVD) is one major subtype of vulvar pain, affecting close to one in ten women and resulting in pain during attempts at vaginal intercourse and/or attempts to insert a digit, device or tampon into the vagina. Management involves a multidisciplinary approach, through physicians, psychologists, sex therapists and physiotherapists. Low Level Laser Therapy (LLLT) is a therapeutic modality involving irradiation of injured or diseased tissue with a combination of red and infrared light. This process is thought to initiate a series of physiological reactions within the cells exposed to light at these wavelengths, leading to the restoration of normal cell structure and function. The investigators hypothesize that LLLT will be effective at reducing pain and improving sexual function among women with PVD. The purpose of this double-blind randomized controlled trial is to assess the feasibility of using a LLLT intervention for the management of PVD in women. The aim is to determine whether there is evidence of a positive effect of LLLT, delivered using a BioFlexTM laser system (Health Canada Licence No. 7931) and a semi-standardized protocol, in terms of self-reported pain and sexual functioning, physiological responses to pressure applied at the vulvar vestibule, tonic and phasic activation of the PFM and/or corticomotor excitability to the PFMs in women with PVD with or without concurrent vaginismus (VAG) when compared to an identical treatment schedule where sham LLLT is delivered. Women will be recruited from among eighty women with confirmed PVD and PVD+VAG who participate in a cross sectional study investigating pelvic floor muscle involvement in PVD. If they are interested in participating in this intervention study, they will be asked to consent to having their data from the cross sectional study used for the purposes of this concurrent study. Women will be evaluated before the intervention using a battery of physical assessments and questionnaires, re-evaluated on primary outcome measures 3 weeks after initiating the intervention and then re-evaluated using the complete battery of physical assessment and questionnaires at the end of the intervention period. If we secure further funding, a medium term (12 weeks later) follow-up will be added. Physical assessment will include evaluation of pressure-pain threshold, temporal summation of pain, electromyographic (EMG) evaluation of PFM activity, responses of the PFMs to pressure applied at the vulvar vestibule using a custom electronic vulvalgesiometer, motor evoked potential threshold, amplitude, latency and the duration of cortically mediated silent period recorded from the PFMs following transcranial magnetic stimulation. The questionnaires will include the The Vulvar Pain Assessment Questionnaire (VPAQ), the Female Sexual Functioning Index, the Pain Catastrophizing Scale, the Depression Anxiety Stress Scales and the Central Sensitization Inventory. Three weeks and 12 weeks after the first start of treatment, the Global Perception of Improvement and Global patient satisfaction with treatment questionnaires will be administered. These will be repeated 12 weeks after completing treatment if funding becomes available.

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